A catalyst for syngas-to-olefins production, its preparation method and application

Abstract

This invention discloses a catalyst for the preparation of olefins from syngas, its preparation method, and its application. The catalyst, by weight, comprises 20-50 parts of a support and 50-80 parts of an active component; the active component comprises a composition with the following chemical formula: Fe 100 Mo a B b Ni 1.5c P c O x The catalyst is suitable for the production of olefins from syngas, especially for syngas with a low CO / H2 molar ratio, and has the advantages of high efficiency in converting syngas while producing a high olefin-to-alkane ratio in the products.

Description

Technical Field

[0001] This invention belongs to the field of syngas-to-olefins production, specifically relating to a catalyst for syngas-to-olefins production, its preparation method, and its application. Background Technology

[0002] The Fischer-Tropsch synthesis, discovered in 1923 by German scientists Frans Fischer and Hans Tropsch, is a heterogeneous catalytic hydrogenation reaction of CO over a metal catalyst. This method is an important pathway for the indirect liquefaction of coal and natural gas. China's energy resources are characterized by abundant coal, limited natural gas, and scarce oil. The environmental pollution caused by direct coal combustion is receiving increasing attention. Developing processes for converting coal / natural gas into petroleum products via syngas can not only reduce dependence on foreign energy sources but also play a crucial role in addressing the environmental pollution caused by coal combustion.

[0003] The main products of CO hydrogenation in the Fischer-Tropsch process vary depending on the type of metal catalyst used. Generally, Ni catalysts have extremely strong hydrogenation performance and are used in the production of methane from syngas. CN110339855A reports a Ni catalyst for methane production from syngas and its preparation method. Cu / Zn / Mo is mainly used for the production of lower alcohols from syngas, especially methanol, a feedstock for indirect syngas conversion. Fe and Co are widely used as C... 2+ The production of alkenes and alkanes.

[0004] Fischer-Tropsch synthesis is a strongly exothermic chemical process, especially when the products are mainly light organic hydrocarbons with carbon chain lengths of less than 20. The adiabatic temperature rise can reach 1500℃. When using a fixed bed reactor, heat removal is difficult, leading to temperature runaway and catalyst deactivation. Fluidized beds effectively overcome these problems. Fluidized beds generally use iron-based catalysts. However, iron-based Fischer-Tropsch catalysts are typically used for converting coal-based syngas with a high CO / H2 ratio. When used for converting natural gas-based syngas with a lower CO / H2 ratio, they exhibit a higher selectivity for alkanes but a lower selectivity for olefins. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a catalyst for the preparation of olefins from syngas, its preparation method, and its applications. The catalyst is suitable for the reaction of preparing olefins from syngas, especially for the reaction of preparing olefins from syngas with a low CO / H2 molar ratio, and has the advantages of high efficiency in converting syngas while producing a high olefin-to-alkane ratio in the products.

[0006] The first aspect of the present invention provides a catalyst for the preparation of olefins from syngas, wherein the catalyst comprises, by weight, 20 to 50 parts of a support and 50 to 80 parts of an active component;

[0007] On an atomic basis, the active component comprises a composition with the following chemical formula: Fe 100 Mo a B b Ni 1.5c P c O x ,

[0008] Wherein, B includes at least one selected from alkali metals.

[0009] The value of a ranges from 3 to 30;

[0010] The value of b ranges from 0.1 to 10;

[0011] The value of c ranges from 0.05 to 2;

[0012] x represents the total number of oxygen atoms required to satisfy the oxidation states of all elements in the catalyst.

[0013] According to the present invention, the support comprises at least one of oxides of Ti and Zr.

[0014] According to the present invention, B includes at least one of Na, K, Rb, and Cs.

[0015] According to the present invention, the catalyst has a Ni to P molar ratio of 6 to 13:1 on its surface, based on XPS results.

[0016] According to the invention of benzene, the catalyst is microsphere-shaped.

[0017] A second aspect of the present invention provides a method for preparing the catalyst, the method comprising the following steps:

[0018] (1) Fe salt, Mo salt, support, alkali metal source and Ni3(PO4)2 are mixed and pulped to obtain a slurry;

[0019] (2) The slurry obtained in step (1) is spray-dried, shaped, and calcined to obtain the catalyst.

[0020] According to the present invention, the Fe salt in step (1) is a soluble Fe salt; the Mo salt is a soluble Mo salt. The alkali metal source includes at least one of an alkali metal-containing base and a salt.

[0021] According to the present invention, preferably, in step (1), the Fe salt and Mo salt are dissolved in water to form a solution and then mixed with the support, the alkali metal source and Ni3(PO4)2.

[0022] According to the present invention, preferably, an acid-base regulator is added in step (1) to adjust the pH to 1-5; the acid-base regulator is selected in accordance with conventional methods, and ammonia is preferred.

[0023] According to the present invention, preferably, the solid content in the slurry obtained in step (1) is 15-45% by weight.

[0024] According to the present invention, the mixing and pulping temperature in step (1) is 80 to 100°C.

[0025] According to the present invention, the spray forming equipment in step (2) is a spray dryer.

[0026] According to the present invention, the hot air temperature for spray drying in step (2) is 150–350°C. Further, the hot air medium for spray drying is a mixture of air and a non-oxygen gas; preferably, the volume ratio of air to non-oxygen gas in the mixture is 1:3–7; more preferably, the non-oxygen gas is nitrogen.

[0027] According to the present invention, the roasting temperature in step (2) is 450-700°C; the roasting time is 0.3-5h; and the roasting atmosphere is a mixture of nitrogen and air, preferably with a nitrogen to air volume ratio of 2-5:1.

[0028] The third aspect of the present invention provides the application of the above-described catalyst or the catalyst prepared by the above-described method in the synthesis of olefins from syngas.

[0029] According to the present invention, the synthesis gas comprises CO and hydrogen. Preferably, the volume ratio of CO to hydrogen is 1:3.5 to 5.

[0030] According to the present invention, the reaction temperature is 300–400°C; the reaction pressure is 0.5–8 MPa; and the catalyst loading (volume hourly space velocity) is 2500–11500 h⁻¹. -1 .

[0031] Compared with the prior art, the main beneficial effects of the present invention are as follows:

[0032] (1) The catalyst of the present invention comprises, by weight, 20-50 parts of support and 50-80 parts of active component; by atomic ratio, the active component comprises a composition with the following chemical formula: Fe 100 Mo a B b Ni 1.5c P c O x This invention utilizes a specific ratio of Ni and P elements in the composition of an Fe-Mo catalyst, further ensuring that the Ni and P on the catalyst surface are distributed within a certain ratio range. This catalyst is particularly suitable for the conversion of syngas to olefins in reactions with low CO / H2 ratios. When used in this reaction, the catalyst offers the advantages of high-efficiency conversion of syngas while producing a high olefin-to-alkane ratio in the products.

[0033] (2) In the preparation method of the catalyst of the present invention, Ni3(PO4)2 is added during the preparation of Fe-Mo catalyst to achieve Ni and P doping. The preparation process is controlled, especially the selection of calcination atmosphere and spray forming atmosphere, so that Ni and P on the catalyst surface are distributed in a certain proportion range. This catalyst is particularly suitable for the reaction of preparing olefins from syngas with low molar ratio. It has the advantages of high efficiency in converting syngas and high alkene-to-alkane ratio in the product.

[0034] (3) The catalyst of this invention is suitable for the conversion of syngas to olefins, especially for the conversion of syngas to olefins with low CO / H2 ratio. When applied to this reaction, the catalyst can efficiently convert syngas while maintaining a high olefin-to-alkane ratio, and at the same time solves the problem of catalyst deactivation caused by poor heat removal ability in strongly exothermic reactions. Detailed Implementation

[0035] In this invention, the elemental analysis of the catalyst surface was performed using an EscalLab Xi+ X-ray photoelectron spectroscopy (XPS) instrument.

[0036] In this invention, CO conversion rate (%) is expressed as a mass fraction.

[0037] In this invention, C2 + Hydrocarbon selectivity (%) is expressed as a mass fraction. C2 + Hydrocarbons include C2 + Olefins, C2 + Alkanes.

[0038] In this invention, C2 + Alkenes are alkenes with 2 to 20 carbon atoms. (C2) + Alkanes are alkanes with 2 to 20 carbon atoms.

[0039] In this invention, C2 + Olefins / C2 + Alkanes are the molar ratio of alkenes with 2 to 20 carbon atoms to alkanes with 2 to 20 carbon atoms.

[0040] In this invention, the catalyst evaluation methods for Examples 1-5 and Comparative Examples 2-4 are as follows:

[0041] The catalyst is reduced using an in-situ reduction method. After the reduction is complete, the process conditions are switched directly to the synthesis reaction conditions in the reactor used for the reduction to start the reaction.

[0042] Reactor specifications: Millimeter fluidized bed reactor;

[0043] Catalyst loading: 50 grams;

[0044] The reduction conditions are: temperature 450℃

[0045] Pressure 0.1MPa

[0046] Catalyst loading (standard volume hourly space velocity) 6000 hours -1

[0047] reducing gas H2

[0048] Restoration time: 12 hours

[0049] The synthesis reaction conditions were: reaction temperature 360℃.

[0050] Reaction pressure 1.5 MPa

[0051] Catalyst loading (standard volume hourly space velocity) 6000 hours -1

[0052] The feedstock ratio (moles) in the synthesis gas is CO / H2 = 1:4

[0053] The reaction ran for 100 hours.

[0054]

Example 1

[0055] Dissolve 1 mol of Fe(NO3)3·9H2O in water to prepare a 0.5 mol / L Fe elemental solution I; dissolve 0.03 mol of ammonium heptamolybdate to prepare a 0.5 mol / L Mo aqueous solution II; take 115 g of... A 40wt% zirconium sol containing ZrO2, a 40wt% KOH solution containing 0.04 mol K, and a 40wt% nickel phosphate solution containing 0.002 mol Ni3(PO4)2 were mixed with solutions I and II and stirred at 90°C. Simultaneously, the pH of the mixture was adjusted to 5 with 25wt% ammonia water, and the solid content of the mixture was adjusted to 35% with water to obtain slurry III. The slurry was then spray-dried and shaped using a spray gun with an inlet temperature of 350°C and an outlet temperature of 200°C. The hot air medium in the spray gun was a mixture of air and nitrogen at a volume ratio of 1:5. The resulting spray-dried material was then calcined at 650°C for 2 hours under a low-oxygen atmosphere with a nitrogen to air volume ratio of 3 to obtain a catalyst. The catalyst composition was: 50wt% Fe 100 Mo 21 K4Ni 0.6 P 0.4 O x +50wt% ZrO2.

[0056] XPS analysis showed that the molar ratio of Ni to P on the surface of the prepared catalyst was 10:1.

[0057] The reaction results of the catalyst evaluation test are shown in Table 1.

[0058]

Example 2

[0059] Dissolve 1 mol of Fe(NO3)3·9H2O in water to prepare a 0.5 mol / L Fe elemental solution I; dissolve 0.03 mol of ammonium heptamolybdate to prepare a 0.5 mol / L Mo aqueous solution II; take 115 g of... A mixture of 40 wt% zirconium sol (ZrO2), 40 wt% KOH solution (containing 0.04 mol K), and 40 wt% nickel phosphate solution (containing 0.006 mol Ni3(PO4)2) was mixed with solutions I and II and stirred at 90°C. The pH of the mixture was adjusted to 5 with 25 wt% ammonia, and the solid content was adjusted to 35% with water to obtain slurry III. The slurry was then spray-dried to obtain a spray-dried material. The sprayer inlet temperature was 350°C, the outlet temperature was 200°C, and the hot air medium was a mixture of air and nitrogen at a volume ratio of 1:5. The dried material was then calcined at 650°C for 2 hours under a low-oxygen atmosphere with a nitrogen to air volume ratio of 3 to obtain a catalyst. The catalyst composition was: 50 wt% Fe. 100 Mo 21 K4Ni 1.8 P 1.2 O x +50wt% ZrO2.

[0060] XPS analysis showed that the molar ratio of Ni to P on the surface of the prepared catalyst was 12:1.

[0061] The reaction results of the catalyst evaluation test are shown in Table 1.

[0062]

Example 3

[0063] Dissolve 1 mol of Fe(NO3)3·9H2O in water to prepare a 0.5 mol / L Fe elemental solution I; dissolve 0.03 mol of ammonium heptamolybdate to prepare a 0.5 mol / L Mo aqueous solution II; take 115 g of... A 40wt% zirconium sol containing ZrO2, a 40wt% KOH solution containing 0.04 mol K, and a 40wt% nickel phosphate solution containing 0.00025 mol Ni3(PO4)2 were mixed with solutions I and II and stirred at 90°C. Simultaneously, the pH of the mixture was adjusted to 5 with 25wt% ammonia water, and the solid content of the mixture was adjusted to 35% with water to obtain slurry III. The slurry was then spray-dried to obtain a spray-dried material. The sprayer inlet temperature was 350°C, the outlet temperature was 200°C, and the hot air medium was a mixture of air and nitrogen at a volume ratio of 1:5. The dried material was then calcined at 650°C for 2 hours under a low-oxygen atmosphere with a nitrogen to air volume ratio of 3 to obtain a catalyst. The catalyst composition was: 50wt% Fe 100 Mo 21 K4Ni 0.075 P 0.05 O x+50wt% ZrO2.

[0064] XPS analysis showed that the molar ratio of Ni to P on the surface of the prepared catalyst was 6:1.

[0065] The reaction results of the catalyst evaluation test are shown in Table 1.

[0066]

Example 4

[0067] Dissolve 1 mol of Fe(NO3)3·9H2O in water to prepare a 0.5 mol / L Fe elemental solution I; dissolve 0.03 mol of ammonium heptamolybdate to prepare a 0.5 mol / L Mo aqueous solution II; take 115 g of... A 40wt% zirconium sol containing ZrO2, a 40wt% KOH solution containing 0.04 mol K, and a 40wt% nickel phosphate solution containing 0.002 mol Ni3(PO4)2 were mixed with solutions I and II and stirred at 90°C. Simultaneously, the pH of the mixture was adjusted to 5 with 25wt% ammonia water, and the solid content of the mixture was adjusted to 35% with water to obtain slurry III. The slurry was then spray-dried and shaped using a spray gun with an inlet temperature of 350°C and an outlet temperature of 200°C. The hot air medium in the spray gun was a mixture of air and nitrogen at a volume ratio of 1:5. The resulting spray-dried material was then calcined at 650°C for 2 hours under a low-oxygen atmosphere with a nitrogen to air volume ratio of 3 to obtain a catalyst. The catalyst composition was: 50wt% Fe 100 Mo 21 K4Ni 0.6 P 0.4 O x +50wt% ZrO2.

[0068] XPS analysis showed that the molar ratio of Ni to P on the surface of the prepared catalyst was 10:1.

[0069] The reaction results of the catalyst evaluation test are shown in Table 1.

[0070]

Example 5

[0071] Dissolve 1 mol of Fe(NO3)3·9H2O in water to prepare a 0.5 mol / L Fe elemental solution I; dissolve 0.03 mol of ammonium heptamolybdate to prepare a 0.5 mol / L Mo aqueous solution II; take 115 g of... A mixture of 40 wt% zirconium sol (ZrO2), 40 wt% RbOH solution (containing 0.04 mol Ru), and 40 wt% nickel phosphate solution (containing 0.002 mol Ni3(PO4)2) was mixed with solutions I and II and stirred at 90°C. The pH of the mixture was adjusted to 5 with 25 wt% ammonia, and the solid content was adjusted to 35% with water to obtain slurry III. The slurry was then spray-dried to obtain a spray-dried material. The sprayer inlet temperature was 350°C, the outlet temperature was 200°C, and the hot air medium was a mixture of air and nitrogen at a volume ratio of 1:5. The dried material was then calcined at 650°C for 2 hours under a low-oxygen atmosphere with a nitrogen to air volume ratio of 3 to obtain a catalyst. The catalyst composition was: 50 wt% Fe. 100 Mo 21 Rb4Ni 0.6 P 0.4 O x +50wt% ZrO2.

[0072] XPS analysis showed that the molar ratio of Ni to P on the surface of the prepared catalyst was 10:1.

[0073] The reaction results of the catalyst evaluation test are shown in Table 1.

[0074]

Comparative Example 1

[0075] Dissolve 1 mol of Fe(NO3)3·9H2O in water to prepare a 0.5 mol / L Fe elemental solution I; prepare a 0.5 mol / L Mo aqueous solution II by dissolving 0.03 mol of ammonium heptamolybdate; and prepare a 40 wt% zirconium sol containing 115 g ZrO2, a 40 wt% KOH solution containing 0.04 mol K, and a 40 wt% nickel phosphate solution containing 0.002 mol Ni3(PO4)2, along with solutions I and II. Liquid II was mixed and stirred at 90°C to form a slurry. Simultaneously, the pH of the mixture was adjusted to 5 with 25wt% ammonia water, and the solid content of the mixture was adjusted to 35% with water to obtain slurry III. The slurry was then spray-dried and shaped using a spray gun with an inlet temperature of 350°C and an outlet temperature of 200°C. The hot air medium in the spray gun was a mixture of air and nitrogen at a volume ratio of 1:5. The resulting spray-dried material was then calcined at 650°C for 2 hours under a low-oxygen atmosphere with a nitrogen to air volume ratio of 3 to obtain a catalyst. The catalyst composition was: 50wt% Fe. 100 Mo 21 K4Ni 0.6 P 0.4 O x+50wt% ZrO2.

[0076] XPS analysis showed that the molar ratio of Ni to P on the surface of the prepared catalyst was 10:1.

[0077] The catalyst evaluation conditions were the same as in the example, except that the feedstock ratio (molar) in the evaluation syngas was CO / H2 = 1:1.5. The test reaction results are shown in Table 1.

[0078] [Comparative Example 2]

[0079] 1 mol of Fe(NO3)3·9H2O was dissolved in water to prepare a 0.5 mol / L Fe elemental solution I. 0.03 mol of ammonium heptamolybdate was used to prepare a 0.5 mol / L Mo aqueous solution II. 40 wt% zirconium sol containing 115 g ZrO2, 40 wt% KOH solution containing 0.04 mol K, and 40 wt% nickel nitrate solution containing 0.006 mol Ni(NO3)2 were mixed with solutions I and II and stirred at 90°C. The pH of the mixture was adjusted to 5 with 25 wt% ammonia water. The solid content of the mixture was adjusted to 35% with water to obtain slurry III. The slurry was spray-dried and shaped. The inlet temperature of the sprayer was 350°C, the outlet temperature was 200°C, and the hot air medium of the sprayer was a mixture of air and nitrogen with a volume ratio of 1:5 to obtain the spray-dried material. Then, it was calcined at 650°C for 2 h in a low-oxygen atmosphere with a nitrogen to air volume ratio of 3 to obtain the catalyst. The catalyst has the following composition: 50 wt% Fe 100 Mo 21 K4Ni 0.6 O x +50wt% ZrO2.

[0080] The reaction results of the catalyst evaluation test are shown in Table 1.

[0081] [Comparative Example 3]

[0082] 1 mol of Fe(NO3)3·9H2O was dissolved in water to prepare a 0.5 mol / L Fe elemental solution I. 0.03 mol of ammonium heptamolybdate was used to prepare a 0.5 mol / L Mo aqueous solution II. 40 wt% zirconium sol containing 115 g ZrO2, 40 wt% KOH solution containing 0.04 mol K, and 40 wt% phosphoric acid solution containing 0.004 mol H3PO4 were mixed with solutions I and II and stirred at 90 °C. The pH of the mixture was adjusted to 5 with 25 wt% ammonia water. The solid content of the mixture was adjusted to 35% with water to obtain slurry III. The slurry was spray-dried and shaped. The inlet temperature of the sprayer was 350 °C, the outlet temperature was 200 °C, and the hot air medium of the sprayer was a mixture of air and nitrogen with a volume ratio of 1:5 to obtain the spray-dried material. Then, it was calcined at 650 °C for 2 h in a low-oxygen atmosphere with a nitrogen to air volume ratio of 3 to obtain the catalyst. The catalyst has the following composition: 50 wt% Fe 100 Mo 21 K4P 0.4 O x +50wt% ZrO2.

[0083] The reaction results of the catalyst evaluation test are shown in Table 1.

[0084] [Comparative Example 4]

[0085] 1 mol of Fe(NO3)3·9H2O was dissolved in water to prepare a 0.5 mol / L Fe elemental solution I. 0.03 mol of ammonium heptamolybdate was used to prepare a 0.5 mol / L Mo aqueous solution II. 40 wt% zirconium sol containing 115 g ZrO2, 40 wt% KOH solution containing 0.04 mol K, and 40 wt% nickel phosphate solution containing 0.002 mol Ni3(PO4)2 were mixed with solutions I and II and stirred at 90°C. Simultaneously, the pH of the mixture was adjusted to 5 with 25 wt% ammonia water. The solid content of the mixture was adjusted to 35% with water to obtain slurry III. The slurry was spray-dried and shaped using a spray gun with an inlet temperature of 350°C and an outlet temperature of 200°C. Air was used as the hot air medium in the spray gun. The spray-dried material was then calcined at 650°C for 2 hours in an air atmosphere to obtain a catalyst. The catalyst composition was: 50 wt% Fe. 100 Mo 21 K4Ni 0.6 P 0.4 O x +50wt% ZrO2.

[0086] XPS analysis showed that the molar ratio of Ni to P on the surface of the prepared catalyst was 20:1.

[0087] The reaction results of the catalyst evaluation test are shown in Table 1.

[0088] Table 1

[0089] catalyst CO conversion rate (%) <![CDATA[C2 + Hydrocarbon selectivity (%) <![CDATA[C2 + Olefins / C2 + Alkanes Example 1 92 91 5.6 Example 2 90 88 7.2 Example 3 89 89 6.7 Example 4 91 93 5.8 Example 5 93 90 5.7 Comparative Example 1 58 90 5.7 Comparative Example 2 95 63 1.3 Comparative Example 3 73 71 2.4 Comparative Example 4 72 48 0.3

[0090] The specific embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combining the various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A catalyst for the preparation of olefins from syngas, characterized in that, The catalyst, by weight, comprises 20-50 parts of support and 50-80 parts of active component; On an atomic basis, the active component comprises a composition with the following chemical formula: Fe 100 Mo a B b Ni 1.5c P c O x , Wherein, B includes at least one selected from alkali metals. The value of a ranges from 3 to 30; The value of b ranges from 0.1 to 10; The value of c ranges from 0.05 to 2; x represents the total number of oxygen atoms required to satisfy the oxidation states of all elements in the catalyst. The molar ratio of Ni to P on the catalyst surface is 6~13:

1.

2. The catalyst according to claim 1, characterized in that, The support comprises at least one oxide of Ti and Zr; and / or, the B comprises at least one oxide of Na, K, Rb, and Cs.

3. A method for preparing the catalyst according to any one of claims 1 to 2, comprising the following steps: (1) Fe salt, Mo salt, support, alkali metal source and Ni3(PO4)2 are mixed and pulped to obtain slurry; (2) The slurry obtained in step (1) is spray-dried, shaped, and calcined to obtain the catalyst.

4. The preparation method according to claim 3, characterized in that, In step (1), add an acid-base regulator to adjust the pH to 1-5.

5. The method for preparing the catalyst according to claim 3, characterized in that, The solid content of the slurry obtained in step (1) is 15-45% by weight.

6. The method for preparing the catalyst according to claim 3, characterized in that, In step (2), the hot air temperature for spray drying is 150~350℃.

7. The method for preparing the catalyst according to claim 6, characterized in that, In step (2), the hot air medium for spray drying is a mixture of air and non-oxygen gas.

8. The method for preparing the catalyst according to claim 7, characterized in that, In step (2), the volume ratio of air to non-oxygen gas is 1:3~7.

9. The method for preparing the catalyst according to claim 7, characterized in that, In step (2), the non-oxygen gas is nitrogen.

10. The method for preparing the catalyst according to claim 3, characterized in that, The roasting temperature in step (2) is 450~700℃; the roasting time is 0.3~5h.

11. The method for preparing the catalyst according to claim 10, characterized in that, In step (2), the roasting atmosphere is a mixture of nitrogen and air.

12. The method for preparing the catalyst according to claim 11, characterized in that, In the roasting atmosphere of step (2), the volume ratio of nitrogen to air is 2~5:

1.

13. The use of the catalyst according to any one of claims 1 to 2 or the catalyst prepared by any one of claims 3 to 12 in the synthesis of olefins from syngas.

14. The application according to claim 13, characterized in that, The synthesis gas consists of CO and hydrogen.

15. The application according to claim 14, characterized in that, In the synthesis gas, the volume ratio of CO to hydrogen is 1:3.5~5.